I have a Pi2 & DAC+ and I want to add a proto board for 7 additional GPIO (1 LED out, 1 digital out, 1 digital in + 4 switch inputs). The digital I/O is for a Mausberry power supply: http://mausberry-circuits.myshopify.com/pages/setup
I have seen this page: https://www.hifiberry.com/guides/gpio-usage-of-the-hifiberry-products/
so, it seems that the Mausberry defaults of GPIO 23,24 should be fine, I am thinking GPIO 5,6,12,13 for the switches, and GPIO 16 for the LED output.
I also see the 40 holes next to the 40 pin header on the DAC+, I'm assuming those connect to the 40 pin header?
Has anybody found a nice thru-hole protoboard that stacks onto the DAC+ easily? I doubt I'll need more than a dozen components on it before I'm done, so I'd like to keep it to roughly the size of the Pi2/DAC+ stack - ideally something that would stack up with some standoffs.